When rebuilding a drain field, is it imperative to dig individual trenches for each "tine" of the drain pipe "fork", or would it be possible to just dig one big hole to lay all the piping down. If I can just dig one big hole, I can just rent a skid steer. If I need to dig trenches, I'll have to rent a backhoe.
How deep below grade do the pipes need to be? I live in a place where frost typically reaches 6 feet or deeper before spring melt.
How much crushed rock needs to be beneath the pipes? Is there a limit to how deep the crushed rock can be? Is there a benefit of greater field capacity with deeper gravel?
Thanks.
Best Answer
Based on your rather telling but incomplete information, I have to caution you on your plans. This may have changed, I haven't had septic in 20-years. Not good & not legal, if the field hasn't been unused for 20-years. This must be fully designed, tested, approved & inspected to be proper, legal & last 25 or more years.
If a newer field has to be re-used, all soil needs to be entirely removed & replaced with a proper draining & absorption mixture. A complete & total deep excavation. The fork must be a fork & not a single long pipe & no fork tine can be any longer than 100' & each must end with an inspection vent pipe. Each tine must be separated by dirt to avoid pooling & enforce even distribution.